Many books have been written on the various escapements, describing their action, construction and proportion, and the laws governing the same; learned writers have contributed much valuable information on adjusting; excellent attachments for the various lathes have been invented; and factories have expended fortunes to produce machinery of wonderful construction to finish all the parts of a watch in the most approved manner; but all this scientific research, all this painstaking effort, all this care and labor, are rendered abortive by the maker or repairer of a time piece if he does not thoroughly understand and apply the physical laws which govern the science of lubrication.

Many a watch, or chronometer, most excellent in all other respects, has come to an untimely end by an almost criminal neglect on the part of its maker to provide against wear in its various parts by such construction as would retain the oil at the places needed.

How often the repairer—clean he his work as well as he may—replace he the broken or worn part to put the time piece in as good condition as new—finds that its rate changes, that is loses time before long, and, at the end of one year is badly out of repair, solely the result of lack of knowledge, or negligence, in properly lubricating, or on account of an oil having been used which was not suitable.

The object of this paper is to present in concise form the best of that which is furnished by the literature of the profession, together with that which has been written on friction and lubrication in general (so far as it may be applicable), by those not connected with this particular vocation; as well as the result of the practical experience of the manufacturers of time pieces in this country most of whom have furnished much useful data in answer to queries on the subject. The manufacturers of oils have also assisted by contributing valuable information.

The result of the author's experience, observation and experiments will also be incorporated; and he will be grateful to any who may read this work, who will call attention, through the trade papers, to any errors of omission or commission that they may find therein.